The intersection of Kraemer Boulevard and Crowther Avenue was closed for about two years so that the undercrossing could be completed. As part of the $67-million project, temporary railroad tracks were built south of the current tracks. That rail traffic will now shift back to the mainline and motorists and pedestrians will safely pass underneath.

The Kraemer Boulevard project is one of seven bridges or undercrossings being built as part of the $630-million O.C. Bridges program. The goal of each of the projects is to enhance safety and improve commute times by eliminating the need for drivers to wait at rail crossings.

Up to 70 trains, some more than a mile long, travel through the area daily. That number is expected to increase to nearly 130 daily trains by 2030.

"Each of these new bridges along the rail line help improve the quality of life for the people who travel through North County with enhanced safety and quicker commutes," said OCTA Chairman Shawn Nelson, also the chairman of the Orange County Board of Supervisors. "We appreciate people's patience through the construction and we're excited to have Kraemer open to traffic once again."

Construction on the final three projects in the O.C. Bridges program – at State College Boulevard, Raymond Avenue and Lakeview Avenue – began in May. Construction on those projects is expected to finish by 2018.

Finishing touches on the Kraemer Boulevard project, including additional landscaping and signage, will continue. A completion celebration with transportation and city officials is planned at the new underpass on July 8.